C. Use the equation C(s) + 2H2(g) CH4(g), ΔH = –74.85, for the following questions. (5 points)
i. Is the formation of methane (CH4) an exothermic or endothermic reaction? (1 point)

ii. Draw a potential energy diagram for the reaction. (2 points)

iii. Label the graph with the following: "Reactants," "Products," "ΔHreaction," and "Ea." (2 points)

im pretty sure its b

i think its 100.

hope this !

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2